How much sleep do I need every night?

Sleep need is individual. It's like height. Some of us are short, some of us are tall. Some of us are short sleepers; some of us are long sleepers.

In general anywhere between four and eleven hours could be considered normal. The main issue is that you get that amount of sleep - whatever it may be. So if you're a four-hour-a-night person, you need to get four hours - which, let's be honest, shouldn't be that difficult. But if you're an eleven-hour-a-night person, getting those eleven hours is going to be problematic.

"The way you know what the right amount of sleep for you is how you feel the next day. If you feel awake during the day you've had enough; if you feel sleepy, you haven't. It's as simple as that."

Most people are between seven and nine hours, and all the recommendations that came out last year from the American Academy of Sleep Medicine recommend getting more than seven hours on average per night. But the idea that we should all be getting eight-hours is a myth - it's about getting the right amount of sleep for you. The way you know what the right amount of sleep for you is how you feel the next day. If you feel awake during the day you've had enough; if you feel sleepy, you haven't. It's as simple as that.

There has been some recent work stating that women need more sleep than men because there are more activities that women carry out. Men are pretty simple, we're designed to hunt and protect, while women are designed to worry about food, children and that sort of thing. So it seems women need more sleep -perhaps 20-30 minutes more a night. But that's as an overall average.

"In our modern society we don't listen to our bodies. We go to bed when the TV programme we've been watching has finished, or when our partner goes to sleep."

In the past we listened to our bodies. If we were sleepy in the evening we went to sleep and we woke up when we'd had enough sleep. In our modern society we don't listen to our bodies. We go to bed when the TV programme we've been watching has finished, or when our partner goes to sleep. And we get up as a social construct - we get up because we have to go to work. So we're not living in harmony with our bodies and that's what is creating the problem.

People spend a lot of time thinking about diet and exercise and doing those correctly, but we don't think about doing sleep correctly. We don't prioritise sleep. It's the thing we do after we've done everything else. Instead of "Oh, I'm sleepy, it's nine o'clock, I'll go to bed", it's "I go to bed at 11 o'clock." But if you're sleepy before that time you should go to bed. We should be listening to our bodies. If you're feeling sleepy, you shouldn't be going to bed because of what the clock says or what's on the TV. You should be going to bed to go to sleep.